Tinning machine



Oct 3L 1950 G. w. LATHEM ETAL 2,527,744

TINNING MACHINE Filed Sept. l2, 1946 Patented Oct. 31, 1950 Rodgers, Birmingham, Ala., assgnors to Ten nessee Coal, Iron and RailroadCompany, a cor ,Y t

poration of Alabama Application September 12, 1946, Serial No. 696,602

This inventionl rrelates to improvements in tirming machines, and more particularly rto `mechanism forfeeding tin plate or sheets from such machines after they have received the conventional metal coating and while they are inthe usual palm Oil bath.Y f

A, In the past, considerable diiiculty has been experienced, in conveying tin plates through and from the usual liquid metal and palm oil baths. The tin plates as they emerge from the metal bath are conveyed by means of a plurality of rolls upwardly through the palm oil onev at a time. The effect of these rolls is to pinch the plates as they come through and remove excess liquid metal from their surfaces before the metal coating solidifies after leaving the palm oil bath. It will be readily apparent that the surfaces of the feeding rolls must be kept in perfect condition, otherwise there will be imperfections in the coated surfaces of the plates or sheets. In other words, if the tin on the plates had impurities or sediment from the metal and palm oil baths which collected on the roll surfaces and were not removed, uneven contact with the plates or sheets would result. Uneven protuberances on the surfaces of the rolls will produce what is known in the art as freckles on the coated surfaces of the finished plate, while indentations in the roll surfaces, however slight, will cause slobbers on the plate surfaces.

. Various types of materials have been used for wiping the rolls in an attempt to prevent freckles and slobbersf but none have proved to be entirely satisfactory. For example, soapstone and asbestos'have been used, but soapstone does not wipe enough 'While asbestos wipes too much.

It is therefore an object of our invention to provide a brush which wipes and polishes the surfaces of the rolls in order to obtain perfectly coated plates. l

This and other objects will be more apparent after referring to the following drawings, in which:

Figure 1 is a sectional elevation of a conventional tinning machine with its usual sheet or plate feeding mechanism.

Figure 2 is a View taken on the line II-II of Figure 1.

Referring more particularly to the drawing, the numeral 2 designates a conventional tinning machine, or tin pot, which contains the usual liquid metal 3 with the palm oil bath 4 floating on its surface.

In accordance with conventional practice, the

plates or sheets are fed into the pot 2 by Vmeans of a pair of pinch-rolls which are positioned below thev surface of the liquid metal. The'sheets or plates are deflected upwardly out of the metal bath by means of a deflector plate 6, and into the palm oil bath d. A plurality of pairs of rolls are vdisposed beneath the surface of the palm oil for squeezingthe surplus liquid metal from theA surfaces of the sheets or'plates' and conveying them upwardly out of the palm oil and tin pot. These groups of rolls are indicated in the drawing at '1, 8 and 8, and are each provided .with a brush for maintaining the roll surface perfectly smooth and oil il in order to feed the sheets or plates out of y the tinning machine.

Each of the brushes la, 8a .and 9a are held in a suitable trough, generally indicated at l0, each of the troughs being suspended on rods i I which are provided with upper threaded portions l la. The upper threaded portions lla of the rods are extended through suitable apertures in angles l2 which are secured to the upper portion of the v,tinning machine, and resiliently and adjustably hold the brushes against the roll surfaces by means of a spring I4, washer l5, and a nut I6 which is threaded on the end of the rod.

In accordance with the present invention, the brushes la, 8a and 9a are made of a composition which has an effective wiping action and also an effective polishing action on the surfaces of the rolls as they wipe off the molten metal transferred thereto from the tin sheets being conveyed by the rolls out of the palm oil and tin plate. Thus the roll surfaces are given a very line cleaning and polishing. The composition used is preferably a hard and dense mixture of asbestos and Portland cement withV best results being obtained by using between approximately twenty-five to thirty-four per cent asbestos and between approximately seventy-five to sixty-six `per cent hydrated Portland cement. African asbestos has proved to be very satisfactory. One suitable material coming within this range is that known to the trade as Transita If desired, diatomaceous earth and a cement binder may be substituted for the hydrated Portland cement in the vtomaceous earth brushes of the present invention give surprisingly and unexpectedly improved results both in the quality of the tin coating and in the life of the equipment. The amount-ofthe A j asbestos in the brushes can be varied as desired to give different degrees ofA 'wiping 'of the rolls, the greater the wiping action desired the greater will be the per cent of asbestos in the composition. The fibers of the asbestos in the composition giving the wiping action to the rolls While the Portland cement and the diatomaoeous earth give a continuous iine polishing action'to the surface of the steel rolls, thus preventing the formation of the iron tin alloy thereon.

Whilfe two embodiments of our invention have been lshown and described 'it will be apparent thatother adaptations and modifications may be made Without departing from the scope of' the following claims. Y Y

rWefclaim: f

l. A tinning lmachine Vhaving a plurality of 4 sheet feeding rolls and brushes for at least one pair of said rolls, each of said brushes comprising a hard and dense bonded mixture of asbestos and hydrated Portland cement.

2. A tnning machine having a plurality of sheet feeding rolls and brushes for at least one pair of'said rolls, each of said brushes compris- Ving a hard and dense bonded mixture of asbestos and hydrated Portland cement in which the asbestos is present in an amount of from approximately'twenty-ve per cent to approximately thirty-four per cent and the balance is essentiallyl hydrated lPortland cement.

The following references are of record in the le of this patent: 

